CN116194294A

CN116194294A - Laminate comprising polyorganosiloxane cured film, use thereof, and method for producing same

Info

Publication number: CN116194294A
Application number: CN202180061316.XA
Authority: CN
Inventors: 福井弘; 外山香子; 赤坂昌保; 津田武明
Original assignee: Dow Corning Toray Co Ltd
Current assignee: DuPont Toray Specialty Materials KK
Priority date: 2020-06-30
Filing date: 2021-06-21
Publication date: 2023-05-30
Also published as: EP4173821A1; JPWO2022004462A1; US20230295432A1; TW202206550A; KR20230029868A; WO2022004462A1

Abstract

The present invention provides a laminate comprising two or more cured polyorganosiloxane films obtained by curing curable polyorganosiloxane compositions having different compositions because of different functions required as dielectric layers and electrode layers, wherein peeling and defects due to insufficient adhesive strength and follow-up properties are less likely to occur at the interface of the cured polyorganosiloxane films constituting the laminate, and a use thereof and a production method thereof. A laminate having a structure in which two or more cured polyorganosiloxane films having different compositions are laminated, wherein the laminated cured polyorganosiloxane films have a structure in which the cured polyorganosiloxane films are chemically bonded at their interfaces, and wherein at least a part of the functional groups of the cured polyorganosiloxane films involved in the curing reaction are common to at least two layers. Preferably, the compositions each contain a hydrosilylation-reactive group and the compositions have different SiH/Vi ratios, and the laminated cured film has a structure that is chemically bonded at the interface thereof by a hydrosilylation reaction.

Description

Laminate comprising polyorganosiloxane cured film, use thereof, and method for producing same

Technical Field

The present invention relates to a laminate formed by laminating at least two cured polyorganosiloxane films, use thereof, a method for producing the laminate, and a production apparatus.

Background

The cured polyorganosiloxane having a polysiloxane skeleton is excellent in transparency, electrical insulation, heat resistance, cold resistance, and the like, can be improved in electrical activity by introducing a highly dielectric functional group such as a fluoroalkyl group, and can be easily processed into a film shape or a sheet shape, and therefore is used for various applications such as an adhesive film for various electric/electronic devices and an electroactive film for transducer devices such as actuators, and these cured polyorganosiloxane are classified into a hydrosilylation reaction curing type, a condensation reaction curing type, a peroxide curing type, and the like, depending on the curing mechanism thereof. In particular, since a cured polyorganosiloxane film is cured rapidly by leaving it at room temperature or heating and generates no by-products, a cured polyorganosiloxane film using a hydrosilylation reaction curable polyorganosiloxane composition is commonly used.

On the other hand, when a cured polyorganosiloxane film is used as an electronic material for touch panels and the like, and as an electronic component for display devices, particularly as a transducer material for sensors, actuators and the like, it is necessary to provide an electrode layer on an electroactive film as a dielectric layer. For example, non-patent documents 1 and 2 propose forming an electrode layer excellent in follow-up property with respect to a dielectric layer by forming an electrode layer in which a conductive filler is added to a silicone elastomer matrix excellent in flexibility.

However, when an electrode layer to which a conductive filler is added is to be formed on a cured polyorganosiloxane film as an electroactive film, in particular, the dielectric layer may be displaced (for example, expansion or contraction of an actuator or the like), and interfacial separation between the dielectric layer and the electrode layer may occur, which may lead to poor conduction and reduced reliability as an actuator. The applicant of the present application and the like proposed that, although patent document 3 and the like propose to coat a curable polyorganosiloxane composition containing an electroconductive filler on a polyorganosiloxane cured film as an electroactive film, an electrode layer as a polyorganosiloxane cured film is formed on the electroactive film (=dielectric layer), the problem of peeling accompanying insufficient follow-up of an electrode surface as a transducer material for an actuator and the like is not completely solved, and there is still room for improvement.

Prior art literature

Non-patent literature

Non-patent document 1: kujawski, m.; pearse, J.D.; smela, e.carbon 2010, 48, 2409-2417.

Non-patent document 2: rosset, s.; shea, H.R.appl.Phys.A.2013, 110, 281-307.

Patent literature

Patent document 1: international patent publication WO2014/105959

Disclosure of Invention

Problems to be solved by the invention

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a laminate in which two or more cured polyorganosiloxane films obtained by curing curable polyorganosiloxane compositions having different compositions are laminated, which is less likely to cause peeling and defects due to insufficient adhesive strength and follow-up properties at the interface of the cured films constituting the laminate, because the functions required as dielectric layers and electrode layers are different from each other, and to provide a use of the laminate and a method for producing the laminate.

Solution for solving the problem

The present inventors have conducted intensive studies and as a result, have found that the above-described problems can be solved by a laminate having a structure in which two or more cured polyorganosiloxane films having different compositions are laminated, and the laminated cured polyorganosiloxane films have a structure in which the cured polyorganosiloxane films are chemically bonded at the interfaces thereof, and that the cured polyorganosiloxane films of two or more layers are obtained by curing a curable polyorganosiloxane composition in common with at least a part of functional groups involved in curing reactions.

Here, at least one of the polyorganosiloxane cured material films after lamination is an electrode layer obtained by curing a composition containing conductive fine particles; the other side may be a dielectric layer formed by curing a composition having a dielectric functional group or containing no conductive fine particles. It is further preferable that each composition having a different composition of the cured polyorganosiloxane provided on top of each other contains a curing reactive group that cures by a hydrosilylation reaction, and that the amount of the silicon atom-bonded hydrogen atom in the composition is different relative to 1 mol of the total amount of carbon-carbon double bonds in the composition, and that the cured polyorganosiloxane film after lamination has a structure that is chemically bonded by a hydrosilylation reaction at the interface thereof.

Advantageous effects

According to the present invention, there can be provided a laminate in which two or more cured polyorganosiloxane films having mutually different compositions are alternately laminated before curing, wherein problems such as peeling and defects due to insufficient adhesive strength and follow-up properties are less likely to occur at the interface between the cured films, and a use and a production method thereof. In particular, according to the present invention, it is possible to provide a laminate having a structure in which polyorganosiloxane cured films each having the functions of an electrode layer and a dielectric layer are alternately laminated, which is cured by a hydrosilylation reaction, and which is less likely to cause interfacial peeling between the films, poor current conduction, and excellent in reliability in applications such as actuators, and a method for producing the laminate.

Detailed Description

[ laminate ]

The laminate of the present invention is characterized by having a structure in which two or more cured polyorganosiloxane films having different compositions are laminated, and the laminated cured polyorganosiloxane films have a structure in which the cured polyorganosiloxane films are chemically bonded at the interfaces thereof, and the two or more cured polyorganosiloxane films are obtained by curing a curable polyorganosiloxane composition that is common to at least a part of the functional groups involved in the curing reaction. The polyorganosiloxane cured product film may be laminated in three or more layers, and three or more different polyorganosiloxane cured product films may be laminated as long as the compositions before curing are different from each other. The laminate of the present invention may have a multilayer structure of two or more layers, and as long as at least a part of the laminate has a structure in which two types of cured polyorganosiloxane films having different compositions are laminated, the other laminated part has a structure in which cured polyorganosiloxane films of the same kind are laminated (for example, a part of the laminate has a structure in which cured film having a function of a dielectric layer is laminated in order to increase the thickness). In particular, it is particularly preferable that a part or the whole of the laminate has a structure in which two types of polyorganosiloxane cured films having different compositions (for example, cured films as dielectric layers and electrode layers) are alternately laminated.

As an example, when the polyorganosiloxane cured product films L1, L2, and L3 having different compositions before curing are laminated, the whole or part of the laminate is preferably shown by way of example, if the interface is denoted by "/". The term "[ ] n refers to a laminated structure in which the structure in parentheses is repeated n times or more, and n is independently a number of 0 or more. The term "/" means that the layers are opposed to each other in the lamination direction of the laminate (typically, in the thickness direction perpendicular to the surface of each functional layer).

L1/L2；L1/[L2/L1]n/L2/L1；L2/[L1/L2]n/L1/L2；L2/L1/[L1/]n/L2；L1/L2/L3；L1/L2/L3/L4。

When the laminate of the present invention is used for transducers (sensors, actuators, generators), it is preferable that the polyorganosiloxane cured film as the electrode layer is laminated on at least one surface of the polyorganosiloxane cured film as the dielectric layer, and the laminated polyorganosiloxane cured film has a structure in which the polyorganosiloxane cured film is chemically bonded to the interface thereof. Specifically, in the above-described laminate structure, L1 is a cured polyorganosiloxane film serving as a dielectric layer, L2 is a cured polyorganosiloxane film serving as an electrode layer, and the laminate structure preferably has a structure in which these layers are alternately laminated, represented by L2/[ L1/L2] n/L1/L2, and the electrode layer is disposed on the outside. The dielectric layer as L1 may be replaced with a multilayer structure of one layer or two or more layers such as L1/[ L1/] n. Of course, the multi-layer dielectric layer may also have a chemically bonded structure at its interface and is preferred.

The laminate of the present invention may further include a pressure-sensitive adhesive layer used for the purpose of being disposed in the transducer, and optionally a non-silicone thermoplastic resin layer having a release surface, in addition to the electrode layer and the dielectric layer, which is a single layer or a plurality of layers. In particular, when the laminate is used as a member for an electronic device, a combination of a dielectric layer and an electrode layer, a dielectric layer and a pressure-sensitive adhesive layer, or an electrode layer and a pressure-sensitive adhesive layer are preferably chemically bonded at an interface ("/") thereof is shown as an example of the laminate structure. The following combinations are examples, and needless to say, the present invention is not limited to these, and a laminate having symmetry may be not used as shown in some examples. Further, in the examples, examples of the respective functional layers are as follows, "/" is the same meaning as described above.

(L1) a single-layer or multilayer high dielectric sheet comprising a polymer cured product having a dielectric functional group: (EAP).

(L2) Silicone pressure-sensitive adhesive layer: (PSA).

(L3) electrode layer: (EL).

(L4) a non-silicone thermoplastic resin layer: (PF).

Example 1: PSA/EAP/PSA.

Example 2: PSA/EL/EAP/EL/PSA.

Example 3: PSA/PF/EAP/PF/PSA.

Example 4: PSA/EL/PF/EAP/PF/EL/PSA.

Example 5: PSA/PF/EL/EAP/EL/PF/PSA.

Example 6: PF/PSA/EL/EAP/EL/PSA/PF.

Example 7: EL/PSA/EAP/PSA/EL.

Example 8: PF/PSA/EL/EAP/PF/PSA/EL.

Example 9: EL/PSA/EAP/EL.

Example 10: EL/PSA/EAP/EL/PSA.

Example 11: PF/PSA/EAP/PF.

Example 12: PF/PSA/EAP/PF/PSA.

Example 13: EL/PSA/PF/EAP/PF/PSA/EL.

In the laminate of examples 7 and 13 in which the electrode layer was formed on the PSA, the separator was released after the laminate was shipped in a state in which the separator was included on the PSA, and the electrode layer was provided on the PSA. In the laminate in which the non-silicone thermoplastic resin layers of examples 6 and 11 form the outer layer, the laminate may be treated as a member for an electronic device including these resin layers, or may be treated as a releasable laminate having a release surface on the inner surface of the laminate of these resin layers.

In the present invention, a particularly preferred embodiment is a laminate having a structure in which a single or multiple dielectric layers (EAP) and Electrode Layers (EL) are chemically bonded at their interfaces, and is a laminate having a structure in which these layers are alternately laminated, and the whole or part of the electrode layers are arranged outside, as shown by (EL/EAP /) nl. Here, n is a number of 1 or more, and may be stacked in an arbitrary number of repetitions depending on the thickness of the stacked body required for the transducer or the like.

The laminate of the present invention is characterized in that the polyorganosiloxane cured product films having different compositions before curing have a structure in which they are chemically bonded at the interface. In the present invention, since the structure is formed by reacting the curing reactive functional groups contained in each film or the precursor thereof at the interface between the films having different compositions before curing, it is necessary that at least a part of the functional groups participating in the curing reaction of the polyorganosiloxane cured product film described above be common. The type of the curing reaction to be described later is not limited, and may be one type or two or more types, and it is particularly preferable that the cured polyorganosiloxane film after lamination has a structure in which the cured polyorganosiloxane film is chemically bonded at the interface thereof by a hydrosilylation reaction in which an alkenyl group and a silicon atom are bonded to each other. Such bonding can be preferably achieved by a method of producing a curable polyorganosiloxane composition, coating and curing, or a combination thereof, based on adjustment of the content of silicon atom-bonded hydrogen atoms in the composition described later.

The cured polyorganosiloxane film constituting the laminate is not particularly limited in terms of its composition and physical properties, and at least one of them preferably has a volume resistivity of 10 ² Preferably, the particles contain conductive fine particles (particularly preferably fine particles containing at least one conductive carbon selected from conductive carbon black, graphite, and Vapor Grown Carbon (VGCF)) described below. A cured polyorganosiloxane film having such conductivity is suitable for the electrode layer.

At least one of the cured polyorganosiloxane films constituting the laminate preferably has a shear storage modulus (G') at 120 ℃ of 5.0X10 ⁴ Pa～1.5×10 ⁵ Pa. A polyorganosiloxane cured film having such a shear storage modulus is particularly suitable for an electrode layer.

As other mechanical properties, the cured polyorganosiloxane film of the present invention preferably has a compressive residual strain (%) of less than 10%, more preferably less than 5%, and particularly preferably 4% or less.

Further, when the composition for providing a cured polyorganosiloxane film of the present invention is formed into a sheet having a thickness of 2.0mm by heating, it can be designed to have the following mechanical properties measured in accordance with JIS K6249. The composition providing such characteristics is particularly suitable for the dielectric layer, but is not limited thereto.

(1) Young's modulus (MPa) may be set to 0.001 to 10MPa, preferably 0.001 to 2MPa, particularly preferably 0.001 to 1.5MPa at room temperature.

(2) The tear strength (N/mm) may be 1N/mm or more at room temperature, and a particularly preferable range is 2N/mm or more.

(3) The tensile strength (MPa) may be 1MPa or more at room temperature, and a particularly preferable range is 2MPa or more.

(4) The elongation at break (%) may be 50% or more, and particularly preferably ranges from 100% to 1000%.

[ polyorganosiloxane cured film ]

The cured polyorganosiloxane of the present invention is obtained by curing a curable polyorganosiloxane composition into a film. The curing reaction mechanism is not particularly limited, and examples thereof include: hydrosilylation reaction curing based on alkenyl groups bonded to silicon atoms; dehydration condensation reaction curable type and dealcoholization condensation reaction curable type based on silanol groups and/or silicon atom-bonded alkoxy groups; peroxide curing reactive based on the use of organic peroxides; and a radical reaction curing type by irradiation of a mercapto group or the like with a high energy ray, etc., and it is desirable to use a hydrosilylation reaction curing type, a peroxide curing type, a radical reaction curing type, or a combination thereof, from the viewpoint of rapid curing of the whole and easy control of the reaction, and a hydrosilylation reaction curable polyorganosiloxane composition is preferably used. These curing reactions are carried out by heating, irradiation with high-energy rays, or a combination thereof.

Preferably, in the present invention, the curable polyorganosiloxane composition provided with a cured polyorganosiloxane film contains at least:

(A) A polyorganosiloxane having at least two curing-reactive groups containing carbon-carbon double bonds in the molecule;

(B) An organohydrogen polysiloxane having at least two silicon-bonded hydrogen atoms in the molecule, the amount of silicon-bonded hydrogen atoms in the present component being 0.5 to 2.5 moles relative to 1 mole of the total amount of alkenyl groups in the composition; and

(C) An effective amount of a hydrosilylation catalyst.

In the composition for providing a cured polyorganosiloxane film used as a dielectric layer, the component (a) is more preferably a polyorganosiloxane mixture containing:

(a1) A linear or branched polyorganosiloxane having an alkenyl group only at a molecular chain end; and

(a2) The molecule has at least one branched siloxane unit and vinyl [ ]CH ₂ An alkenyl group-containing polyorganosiloxane resin having a content of =ch-) in the range of 1.0 mass% to 5.0 mass%.

The component (a) is a polyorganosiloxane having a curing reactive group containing a carbon-carbon double bond, and examples thereof include linear, branched, cyclic or resinous (network) polyorganosiloxane having a curing reactive group selected from the group consisting of: alkenyl groups having 2 to 20 carbon atoms such as vinyl group; (meth) acryl-containing groups such as 3-acryloxypropyl and 3-methacryloxypropyl.

The polyorganosiloxane as the component (A) may contain a group selected from monovalent hydrocarbon groups having no carbon-carbon double bond in the molecule, hydroxyl groups, and alkoxy groups having 1 to 3 carbon atoms. In addition, in the case of a monovalent hydrocarbon group, a part of hydrogen atoms may be substituted with halogen atoms or hydroxyl groups, and in the case of using as a dielectric layer, a dielectric functional group described later may be introduced. The dielectric functional groups described below are industrially preferable. When component (a) contains a hydroxyl group or the like, the component has condensation reactivity in addition to hydrosilylation reaction curability.

In the case of being used for the dielectric layer, it is preferable that the component (a) may be a polyorganosiloxane represented by the following average composition formula or a mixture thereof.

R ¹ _a R ² _b SiO _(4-a-b)/2

Wherein R is ¹ Are the above-mentioned curing reactive groups containing carbon-carbon double bonds.

R ² Is a group selected from the above monovalent hydrocarbon groups having no carbon-carbon double bond, hydroxyl groups, and alkoxy groups.

a and b are numbers satisfying the following conditions: 1.ltoreq.a+b.ltoreq.3 and 0.001.ltoreq.a/(a+b). Ltoreq.0.33, preferably a number satisfying the following condition: a+b is more than or equal to 1.5 and less than or equal to 2.5, and a/(a+b) is more than or equal to 0.005 and less than or equal to 0.2. The reason for this is that, if a+b is equal to or more than the lower limit of the above-mentioned range, the flexibility of the cured product increases, while, if a+b is equal to or less than the upper limit of the above-mentioned range, the mechanical strength of the cured product increases, and if a/(a+b) is equal to or more than the lower limit of the above-mentioned range, the mechanical strength of the cured product increases, while, if a/(a+b) is equal to or less than the upper limit of the above-mentioned range, the flexibility of the cured product increases.

In the case of use in a dielectric layer, the component (a) of the present invention is particularly preferably a polyorganosiloxane mixture containing the following components.

(a2) Having at least one branched siloxane unit in the molecule, vinyl (CH) ₂ An alkenyl group-containing polyorganosiloxane resin having a content of =ch-) in the range of 1.0 mass% to 5.0 mass%.

The component (a 1) has a siloxane unit represented by the following formula at a molecular chain end thereof.

(Alk)R ² ₂ SiO _1/2

(wherein Alk is an alkenyl group having 2 or more carbon atoms) and the other siloxane unit is substantially represented by R alone ² ₂ SiO _2/2 A linear or branched polyorganosiloxane having a structure of the siloxane unit shown. R is as follows ² The same groups as described above are represented. The degree of polymerization of the siloxane of the component (A1-1) may be in the range of from 102 to 902, inclusive of the terminal siloxane units, in the range of from 7 to 1002. Such component (A1-1) is particularly preferably a molecule chain whose both ends are covered with (Alk) R ² ₂ SiO _1/2 The siloxane units represented are blocked, linear polyorganosiloxanes.

Component (a 2) is an alkenyl group-containing polyorganosiloxane resin.

An alkenyl group-containing polyorganosiloxane resin represented by the following average unit formula is exemplified.

(RSiO _3/2 )o(R ₂ SiO _2/2 )p(R ₃ SiO _1/2 )q(SiO _4/2 )r(XO _1/2 )s

In the above formula, R is a group selected from alkenyl groups and the monovalent hydrocarbon groups having no carbon-carbon double bond, and X is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Wherein said at least one ofOf R, it is preferable that at least vinyl group (CH ₂ In the range where the content of=ch-) is within the range of 1.0 to 5.0 mass%, R is alkenyl, in particular, R ₃ SiO _1/2 At least a portion of R on the siloxane units represented is alkenyl.

In the above formula, (o+r) is a positive number, p is 0 or a positive number, q is 0 or a positive number, s is 0 or a positive number, p/(o+r) is a number in the range of 0 to 10, q/(o+r) is a number in the range of 0 to 5, (o+r)/(o+p+q+r) is a number in the range of 0.3 to 0.9, and s/(o+p+q+r) is a number in the range of 0 to 0.4.

As the component (a 2), an alkenyl group-containing MQ polyorganosiloxane resin represented by the following formula is particularly preferable.

{(Alk)R ² ₂ SiO _1/2 }q1(R ² ₃ SiO _1/2 )q2(SiO _4/2 )r

(wherein, alk, R ² In the same manner as described above, q1+q2+r is a number in the range of 50 to 500, (q1+q2)/r is a number in the range of 0.1 to 2.0, and q2 is a vinyl group (CH) in the polyorganosiloxane resin ₂ The content of =ch-) satisfies a number in a range of 1.0 mass% to 5.0 mass%. )

By using the component (a 1) having an alkenyl group only at the molecular chain end thereof and the component (a 2) having a predetermined amount of alkenyl groups as the polyorganosiloxane resin in combination, a cured product excellent in curability as a whole of the composition and excellent in mechanical strength and flexibility can be provided, and a polyorganosiloxane cured product film particularly suitable for an adhesive layer or a dielectric layer in the above-mentioned electronic parts and the like can be provided.

Component (B) is an organohydrogen polysiloxane having at least two silicon-bonded hydrogen atoms in the molecule, and is a component that functions as a crosslinking agent of component (a).

Examples of such a component (B) include: 1, 3-tetramethyldisiloxane, 1,3,5, 7-tetramethylcyclotetrasiloxane, tris (dimethylhydrosiloxy) methylsilane, tris (dimethylhydrosiloxy) phenylsilane, and both molecular chain terminal trimethylsiloxy end capsMethyl hydrogen polysiloxane, trimethylsiloxy-terminated dimethylsiloxane/methyl hydrogen siloxane copolymer at both ends of molecular chain, dimethylhydrogen siloxy-terminated dimethylsiloxane at both ends of molecular chain, dimethylsiloxy-terminated dimethylsiloxane/methyl hydrogen siloxane copolymer at both ends of molecular chain, trimethylsiloxy-terminated methylhydrogen siloxane/diphenylsiloxane/dimethylsiloxane copolymer at both ends of molecular chain, hydrolytic condensate of trimethoxysilane, and polymer prepared from (CH) ₃ ) ₂ HSiO _1/2 Unit and SiO _4/2 Copolymers of units Composed of (CH) ₃ ) ₂ HSiO _1/2 Unit, siO _4/2 Unit and (C) ₆ H ₅ )SiO _3/2 Copolymers of unit constitution and mixtures of two or more thereof.

The amount of the component (B) used is preferably in the range of 0.1 to 10 moles, more preferably in the range of 0.5 to 2.5 moles, and particularly preferably in the range of 0.5 to 2.0 moles, relative to 1 mole of the carbon-carbon double bond in the component (a) in the composition. When the amount of the component (B) used is less than the lower limit, curing failure may be caused, and when the amount of the component (B) exceeds the upper limit, the mechanical strength of the cured product may become too high, and physical properties preferable as an electrode layer, a dielectric layer, or an adhesive layer may not be obtained. However, in the case of improving the adhesion strength of the cured polyorganosiloxane film of the present invention to an adherend such as glass or the like, the use of silicon-bonded hydrogen atoms in an amount exceeding 20 mol based on 1 mol of carbon-carbon double bonds in the component (a) is not hindered.

The cured polyorganosiloxane films of the present invention preferably have different compositions and a structure in which the components (a) and (B) are chemically bonded to each other at their interfaces by hydrosilylation reaction. Here, the reaction between the component (a) and the component (B) at the interface is preferably performed in the following cases: at the interface between the two cured films or their precursors (including the uncured/semi-cured coated state), the silicon atom-bonded hydrogen atoms (hereinafter, sometimes simply referred to as "SiH/Vi ratio") in the organopolysiloxane component differ by 1 mole relative to the total amount of carbon-carbon double bonds in the cured film or the curable composition providing the cured product. Conversely, if the SiH/Vi ratio is the same, the reaction of the curing reactive functional groups between the interfaces may not be promoted, and a sufficient chemical bond may not be formed.

Preferably, when curable polyorganosiloxane compositions (I) and (II) having different compositions are used, the ratio of SiH/Vi in the composition (I) exceeds 1.0 mol and is 2.0 mol or less (i.e., siH excess), and the ratio of SiH/Vi in the other composition (II) is 0.5 mol or more and 1.0 mol or less (i.e., siH deficiency), whereby the reaction between the common curable reactive functional groups is promoted at the interface between the cured films obtained by curing both, and a strong chemical bond is formed. Regarding the SiH/Vi ratio of the compositions (I) and (II) [ SiH/Vi ]]II/[SiH/Vi] _I The value of (2) is preferably in the range of 0.33 to 0.85, particularly preferably in the range of 0.50 to 0.75 and 0.58 to 0.67. The composition (I) having an excess of SiH may be used as the dielectric layer, and the composition (II) having an excess of SiH may be used as the electrode layer, or the composition (I): the electrode layer, and the composition (II): the dielectric layer) may be used in contrast thereto.

In the present invention, since a strong chemical bond is preferably formed between the cured polyorganosiloxane film serving as the electrode layer and the dielectric layer, when the dielectric layer is provided with the composition (I) and the electrode layer is provided with the composition (II), the difference in composition surface is determined by the presence or absence of conductive fine particles in addition to the SiH/Vi ratio. Specifically, the composition (II) for forming an electrode layer contains conductive fine particles having SiH/Vi ratio ([ SiH/Vi) ] _Elec ) The composition (I) for forming the dielectric layer contains no conductive fine particles and has a SiH/Vi ratio ([ SiH/Vi)] _DEAP ) Particularly preferred is [ SiH/Vi ]] _Elec /[SiH/Vi] _DEAP Has a value of 0.33 to the whole0.85, 0.50 to 0.75, 0.58 to 0.67. That is, it is particularly preferable that the composition for forming the dielectric layer is a combination of a certain degree of SiH excess.

The component (C) is a catalyst for promoting the hydrosilylation reaction of the component (a) and the component (B), and examples thereof are: platinum-based catalyst, rhodium-based catalyst, palladium-based catalyst, nickel-based catalyst, iridium-based catalyst, ruthenium-based catalyst, and iron-based catalyst, preferably platinum-based catalyst. As the platinum-based catalyst, there may be exemplified: platinum fine powder, chloroplatinic acid, an alcohol solution of chloroplatinic acid, a platinum-alkenylsiloxane complex, a platinum-olefin complex, a platinum-carbonyl complex, and a catalyst in which these platinum-based catalysts are dispersed or encapsulated with a thermoplastic resin such as a silicone resin, a polycarbonate resin, or an acrylic resin are particularly preferable. In particular, platinum 1, 3-divinyl-1, 3-tetramethyldisiloxane complex is preferred, and it is preferably added in the form of an alkenylsiloxane solution of the complex. In addition, from the viewpoint of improving the handling workability and the pot life of the composition, a particulate platinum-containing hydrosilylation reaction catalyst dispersed or encapsulated by a thermoplastic resin may also be used. As the catalyst for promoting the hydrosilylation reaction, a non-platinum group metal catalyst such as iron, ruthenium, or iron/cobalt may be used.

The hydrosilylation catalyst as the component (C) may be a hydrosilylation catalyst which does not exhibit activity when irradiated with high-energy rays and exhibits activity in the composition when irradiated with high-energy rays, and may be a high-energy ray-activated catalyst or a photoactivated catalyst. By using such component (C), the following characteristics can be achieved as a whole composition: the curing is effected by irradiation with high-energy rays, and even at low temperatures, the curing is excellent in storage stability, and the reaction is easy to control, so that the workability is excellent.

Examples of the high energy rays include ultraviolet rays, gamma rays, X rays, α rays, and electron beams. In particular, ultraviolet rays, X-rays, and electrons irradiated by a commercially available electron beam irradiation apparatus are exemplifiedAmong them, ultraviolet rays are preferable from the viewpoint of the efficiency of catalyst activation, and ultraviolet rays having a wavelength in the range of 280nm to 380nm are preferable from the viewpoint of industrial utilization. In addition, the irradiation amount varies depending on the type of the high-energy ray-active catalyst, and in the case of ultraviolet rays, the cumulative irradiation amount at a wavelength of 365nm is preferably 100mJ/cm ² ～100J/cm ² Within a range of (2).

Specific examples of the component (C) include: (methylcyclopentadienyl) trimethylplatinum (IV), (cyclopentadienyl) trimethylplatinum (IV), (1, 2,3,4, 5-pentamethylcyclopentadienyl) trimethylplatinum (IV), (cyclopentadienyl) dimethylethylplatinum (IV), (cyclopentadienyl) dimethylacetyl platinum (IV), (trimethylsilylcyclopentadienyl) trimethylplatinum (IV), (methoxycarbonylcyclopentadienyl) trimethylcyclopentadienyl platinum (IV), (dimethylphenylsilylcyclopentadienyl) trimethylcyclopentadienyl platinum (IV), trimethyl (acetyl acetonate) platinum (IV), trimethyl (3, 5-heptanedionate) platinum (IV), trimethyl (methyl acetoacetate) platinum (IV), bis (2, 4-pentanedionate) platinum (II), bis (2, 4-hexanedionate) platinum (II), bis (2, 4-heptanedionate) platinum (II), bis (3, 5-heptanedionate) platinum (II), bis (1-phenyl-1, 3-butanedionate) platinum (II), bis (1, 3-diphenyl-1, 3-propanedionate) platinum (II), bis (hexafluoroacetone) in which, from the viewpoints of versatility and ease of acquisition, (methylcyclopentadienyl) trimethylplatinum (IV) and bis (2, 4-pentanedionate) platinum (II) are preferable.

The amount of the component (C) used is not particularly limited as long as it is an effective amount and is an amount that promotes curing of the curable polyorganosiloxane composition of the present invention. Specifically, the metal atom in the catalyst is preferably in an amount of 0.01 to 1000ppm in terms of mass units, and the platinum metal atom in the component (C) is preferably in an amount of 0.1 to 500ppm, based on the sum of the components (A) to (C) (the total is 100 mass%). The reason for this is that: if the content of the component (C) is less than the lower limit of the above range, curing may be insufficient, and if the content of the component (C) exceeds the upper limit of the above range, coloring, transparency, etc. of the obtained cured product may be adversely affected, in addition to being uneconomical.

[ use of functional filler and function of cured film ]

In the present invention, the cured polyorganosiloxane film after lamination is a cured polyorganosiloxane film obtained by curing curable polyorganosiloxane compositions having different compositions, and it is preferable to blend a functional filler in order to realize the functions thereof. In particular, the composition of the cured polyorganosiloxane film as the dielectric layer is greatly different from that of the cured polyorganosiloxane film as the electrode layer in that it does not contain conductive fine particles, as well as the preferable SiH/Vi ratio. In general, the curable polyorganosiloxane composition provided as the cured film of the electrode layer contains (E) conductive fine particles, and the curable polyorganosiloxane composition provided as the cured film of the dielectric layer preferably contains (F) reinforcing filler, does not contain conductive fine particles, and may optionally further incorporate a highly dielectric functional group. The functional filler may be subjected to a surface treatment for hydrophobization. The surface treatment agent for hydrophobization includes at least one surface treatment agent selected from the group consisting of an organic titanium compound, an organic silicon compound, an organic zirconium compound, an organic aluminum compound, and an organic phosphorus compound.

[ (E) conductive particles ]

The conductive fine particles are not particularly limited as long as they can impart conductivity to the cured polyorganosiloxane film, and a cured film containing the conductive fine particles can be preferably used as an electrode layer. The electrode layer containing conductive fine particles is proposed, for example, in international patent publication WO2014/105959 by the applicant of the present application.

Specifically, there may be mentioned: conductive carbon such as conductive carbon black, graphite, and Vapor Grown Carbon (VGCF); metal powders such as platinum, gold, silver, copper, nickel, tin, zinc, iron, and aluminum, and further include: antimony-doped tin oxide, phosphorus-doped tin oxide, needle-like titanium oxide surface-coated with tin oxide/antimony, tin oxide, indium oxide, antimony oxide, zinc antimonate, carbon, graphite whisker surface-coated tin oxide, and other pigments; a pigment coated with at least one conductive metal oxide selected from the group consisting of tin-doped indium oxide (ITO), fluorine-doped tin oxide (FTO), and phosphorus-doped tin oxide nickel oxide; conductive pigments containing tin oxide and phosphorus on the surface of titanium dioxide particles, and the like, and they may be treated with various surface treating agents. They may be used singly or in combination of two or more kinds. In order to uniformly disperse these conductive fine particles in the curable polyorganosiloxane composition, the conductive fine particles may be blended in the curable polyorganosiloxane composition in the form of a mixture with a part or all of the component (a) or the component (B) used in the composition.

The conductive inorganic fine particles may be fibers such as glass fibers, silica alumina fibers, and carbon fibers; needle-like reinforcing materials such as aluminum borate whiskers and potassium titanate whiskers, and fine particles of conductive materials such as metals coated on the surface of inorganic fillers such as glass beads, talc, mica, graphite, wollastonite, and dolomite.

[ (F) reinforcing filler ]

In the curable polyorganosiloxane composition for providing a cured film as a dielectric layer, it is preferable that the composition contains reinforcing fine particles or a composite thereof having different average BET specific surface areas, which are surface-treated with one or more organosilicon compounds, in a certain range relative to the sum of components forming a nonvolatile solid component by a curing reaction.

Here, from the viewpoint of the mechanical strength of the cured product, the reinforcing fine particles are preferably one or more reinforcing inorganic fine particles having an average primary particle diameter of less than 50nm, and examples thereof include: as the reinforcing fine particles, various metal oxide powders other than fumed silica, wet silica, crushed silica, calcium carbonate, diatomaceous earth, finely crushed quartz, alumina and zinc oxide, glass fibers, carbon fibers, and the like are used, which are treated with one or more types of organosilicon compounds described later. The shape is not particularly limited, and reinforcing fine particles having any shape such as a particle shape, a plate shape, a needle shape, and a fiber shape can be used.

In a preferred example, from the viewpoint of improving the mechanical strength of the dielectric layer, hydrophilic or hydrophobic fumed silica or a metal oxide complex thereof having an average primary particle diameter of 10nm or less and a BET specific surface area different from each other as described later is exemplified as the partial aggregation. Further, from the viewpoint of improving dispersibility, it is preferable to treat fumed silica or a metal oxide composite thereof with disilazane or a silane coupling agent described later. These reinforcing inorganic particles may be used in combination of two or more.

In the present invention, the reinforcing filler for the dielectric layer contains the following components:

(F1) Surface-treated with more than one organosilicon compound and having an average BET specific surface area of more than 100m ² Reinforcing particles/g or complexes thereof; and

(F2) Surface-treated with one or more organosilicon compounds and having an average BET specific surface area of 10m ² /g～100m ² Reinforcing particles or complexes thereof in the range of/g, and

the mass ratio of the component (F1) to the component (F2) is in the range of 50:50 to 99:1, may be in the range of 70:30 to 97:3, and is preferably in the range of 70:30 to 95:5. When the mass ratio is out of the above range, there is a possibility that the viscosity of the curable polyorganosiloxane composition before curing increases, or the mechanical strength and dielectric breakdown strength after curing decrease.

By adding the reinforcing filler as the above-mentioned components (F1) and (F2) to the composition, the mechanical strength and dielectric breakdown strength of the cured polyorganosiloxane obtained by curing the curable polyorganosiloxane composition of the present invention can be increased. The amount of the filler to be blended is in the range of 10 to 40 mass% with respect to the sum of components (F1) and (F2) which form a nonvolatile solid component by a curing reaction in the composition, and may be in the range of 15 to 35 mass%, and particularly preferably in the range of 15 to 30 mass%. If the amount exceeds the upper limit of the above-mentioned mass% range, it may be difficult to apply the curable polyorganosiloxane composition uniformly in a film form, and if the amount is less than the lower limit of the above-mentioned mass% range, the cured physical properties of the curable polyorganosiloxane composition may become insufficient.

The reinforcing filler as the above-mentioned components (F1) and (F2) is preferably surface-treated with one or more organic silicon compounds. The surface treatment with the organosilicon compound is a hydrophobization treatment, and the reinforcing filler surface-treated with the organosilicon compound can be uniformly dispersed in the polyorganosiloxane composition at a high filling rate. In addition, an increase in the viscosity of the composition is suppressed, and the molding processability is improved.

Examples of the organosilicon compound are low molecular weight organosilicon compounds such as silane, silazane, siloxane or the like; silicone polymers or oligomers such as polysiloxanes, polycarbosiloxanes or the like. Preferably, the organosilicon compound used for the surface treatment most preferably contains at least one selected from hexamethyldisilazane and 1, 3-bis (3, 3-trifluoropropyl) -1, 3-tetramethyldisilazane.

In the surface treatment, the proportion of the surface treatment agent to the total amount of the filler is preferably in the range of 0.1 mass% or more and 50 mass% or less, more preferably in the range of 0.3 mass% or more and 40 mass% or less. In the treatment amount, the filler/surface treatment agent loading ratio is preferably such that the remaining treatment agent is removed after the treatment. In addition, there is no problem in using an additive or the like for promoting or assisting the reaction when the treatment is performed as needed.

In the surface treatment, whether the components of the surface treatment agent are chemically or physically fixed to the filler surface is an important parameter. For example, the fixed amount of surface treating agent can be analyzed by reacting an excess of tetraethoxysilane with a composition comprising a filler under alkaline conditions and detecting the reaction product by gas chromatography. The amount of the surface treatment agent fixed to the filler surface may be 1.0 part by mass or more, preferably 3.0 parts by mass or more, based on 100 parts by mass of the filler. Wherein, in the process (F1) for use in connection with the present invention In the case where both hexamethyldisilazane and 1, 3-bis (3, 3-trifluoropropyl) -1, 3-tetramethyldisilazane are used as the surface-treated organosilicon compound of the component (F2), the fixed ratio of each to the filler surface can be changed as needed. For example, in the present invention, as described above, a high dielectric functional group may be introduced into a part or the whole of the component (A) or the component (B) as a group consisting of (C) _p F _2p+1 ) R- (R is an alkylene group having 1 to 10 carbon atoms, and p is an integer of 1 to 8 inclusive). From the viewpoints of dielectric characteristics, economy, ease of preparation, and moldability of the resulting curable polyorganosiloxane composition, the preferable group is a group of p=1, i.e., trifluoropropyl group. In this case, the weight ratio of the treatment components derived from hexamethyldisilazane and 1, 3-bis (3, 3-trifluoropropyl) -1, 3-tetramethyldisilazane to the filler surface may be 0 to 10, preferably 0 to 5. When the amount of the component (a) or (B) is outside this range, the affinity between the component (a) or (B) and the filler surface may be poor, and the processability and physical properties after curing may be degraded.

[ other functional fillers ]

In the curable polyorganosiloxane composition of the present invention, other fillers may be used as desired or may not be used, and examples thereof include a high dielectric filler, thermally conductive inorganic fine particles, and an insulating filler, and these inorganic fine particles may have two or more functions as reinforcing fillers.

Examples of the preferable dielectric inorganic fine particles include one or more inorganic fine particles selected from the group consisting of titanium oxide, barium titanate, strontium titanate, lead zirconate titanate, and composite metal oxides in which part of barium and titanium sites of barium titanate is substituted with alkaline earth metals such as calcium, strontium, yttrium, neodymium, samarium, dysprosium, etc., zirconium, or rare earth metals, more preferably titanium oxide, barium titanate, barium calcium zirconate titanate, and strontium titanate, still more preferably titanium oxide, barium titanate. In particular, the dielectric inorganic fine particles are particularly preferably dielectric inorganic fine particles having a relative dielectric constant of 10 or more at room temperature and 1 kHz. The upper limit of the preferable size (average primary particle diameter) of the inorganic fine particles is 20000nm (20 μm), but 10000nm (10 μm) is more preferable in view of the processability of a thin film for transducer to be described later. By using the dielectric inorganic fine particles, the cured polyorganosiloxane product may further improve mechanical properties and/or electrical properties, in particular, the relative dielectric constant thereof.

The insulating inorganic fine particles used in the present invention are generally known insulating inorganic materials, that is, insulating inorganic fine particles having a volume resistivity of 10 ¹⁰ Ω·cm～10 ¹⁸ The particles of the inorganic material having an Ω·cm are not limited, and any of a particle shape, a sheet shape, and a fiber (including whisker) shape may be used. Specifically, there may be mentioned: examples of preferable use of the spherical particles, plate-like particles or fibers of ceramics include: particles of metal silicates such as alumina, iron oxide, copper oxide, mica, and talc, quartz, amorphous silica, and glass. These may be treated with various surface treating agents described later. They may be used singly or in combination of two or more kinds. By incorporating the insulating inorganic fine particles into the composition, the mechanical strength and dielectric breakdown strength of the cured polyorganosiloxane product can be increased, and an increase in the relative permittivity can be seen in some cases.

Examples of the thermally conductive inorganic fine particles that can be used in the present invention include: metal oxide particles such as magnesium oxide, zinc oxide, nickel oxide, vanadium oxide, copper oxide, iron oxide, and silver oxide; and inorganic compound particles such as aluminum nitride, boron nitride, silicon carbide, silicon nitride, boron carbide, titanium carbide, diamond, and diamond-like carbon, and zinc oxide, boron nitride, silicon carbide, and silicon nitride are preferable. By incorporating one or more of these thermally conductive inorganic fine particles into the composition, the thermal conductivity of the cured polyorganosiloxane product can be increased.

The average particle diameter of these inorganic particles can be measured by a measurement method that is usual in the field. For example, when the average particle diameter is 50nm or more and 500nm or less, the average primary particle diameter can be measured by observing the particle diameter with a microscope such as a Transmission Electron Microscope (TEM), a field emission transmission electron microscope (FE-TEM), a Scanning Electron Microscope (SEM), or a field emission scanning electron microscope (FE-SEM), and obtaining the average value. On the other hand, when the average particle diameter is about 500nm or more, the value of the average primary particle diameter can be directly obtained by a laser diffraction/scattering particle size distribution measuring apparatus or the like.

[ use of solvent ]

The curable polyorganosiloxane composition of the present invention can be used as it is for the curing reaction, but on the other hand, in the case where a part of the composition or its components (for example, polyorganosiloxane resin) is solid or in the case of a viscous liquid, an organic solvent may be used as needed in order to improve the mixing property and handleability thereof. In particular, when the curable polyorganosiloxane composition of the present invention is applied in a film form, the viscosity can be adjusted by using a solvent in the range of 100mpa·s to 50000mpa·s in the overall viscosity, and when diluted with a solvent, the curable polyorganosiloxane composition can be used in the range of 0 to 2000 parts by mass relative to the sum (100 parts by mass) of the components (a) to (C). That is, in the composition of the present invention, the solvent may be 0 parts by mass, and is preferably solvent-free. In particular, by selecting a polymer having a low degree of polymerization in the curable polyorganosiloxane composition of the present invention, there are advantages as follows: the film obtained by curing can be designed to be solvent-free, and no fluorine-based solvent, organic solvent, or the like remains in the film, so that problems of environmental load and influence of the solvent on electronic equipment can be eliminated. The amount of the solvent to be used may be 10 parts by mass or less, preferably 5 parts by mass or less, based on the total (100 parts by mass) of the above-mentioned components (a) to (C), and is preferably a low-solvent composition. In particular, the composition for an electrode layer may be diluted with a solvent and applied in a film form by spraying as described in examples described later.

Preferably, the organic solvent is one or more organic solvents selected from the following solvents or a mixed solvent thereof:

(E1) An organic polar solvent;

(E2) A low molecular siloxane-based solvent; and

(E3) A halogen-based solvent,

it is preferable to use an organic solvent having a boiling point of 80℃or more and less than 200 ℃. The organic solvents may be mixed solvents having different types or different ratios of the same types. Preferably, the organic solvent comprises at least one low molecular siloxane-based solvent selected from hexamethyldisiloxane and octamethyltrisiloxane and a mixed solvent thereof, which are commercially available under the names OST-10, OST-20 and OST-2 from Dow silicone company (DOW SILICONES CORPORATION). In the case where the fluoroalkyl group content in the curable elastomer composition is high, the use of these low-molecular siloxane-based solvents and the halogen-based solvents described above, optionally in combination, is also included in a preferred embodiment of the present invention.

[ bulk viscosity ]

The curable polyorganosiloxane composition used in the present invention has a shear rate of 10.0 (S) at 25 ℃ ^-1 ) The overall viscosity measured below is preferably in the range from 5 mPas to 500000 mPas, particularly preferably in the range from 1000 mPas to 10000 mPas. The amount of the organic solvent used may be adjusted for the purpose of setting the preferable viscosity range, but may be low-solvent type or solvent-free (=solvent-free). The electrode layer composition may be diluted with a solvent, and applied in a film form by spraying, as described in examples described later, and is preferable.

[ thixotropic ratio ]

Preferably, the curable polyorganosiloxane composition of the present invention has excellent fluidity and does not exhibit thixotropic (thixotropic) behavior. Thus, the properties of low overall viscosity and excellent uniform coating property can be achieved. Specifically, the thixotropic ratio of the composition is preferably 10.0 or less, and the thixotropic ratio is at a shear rate of 0.1 (S ^-1 ) The viscosity of the composition as a whole was measured at a shear rate of 10.0 (S ^-1 )(S ^-1 ) The ratio of the viscosities of the entire compositions was measured as follows.

[ amount of solid component ]

In the curable polyorganosiloxane composition of the present invention, the content of the component (in the present invention, sometimes simply referred to as "solid component") that cures to form a cured polyorganosiloxane as a nonvolatile solid component is preferably in the range of 5 to 100 mass%, more preferably in the range of 50 to 100 mass%, 75 to 100 mass%, or 85 to 100 mass% of the entire composition.

[ introduction of dielectric functional group ]

In the case where the polyorganosiloxane cured product film of the present invention is used as an electroactive film (for example, a dielectric film) for a transducer such as an actuator, a high dielectric functional group may be introduced into the cured product. However, even a cured polyorganosiloxane film containing no high dielectric functional group can be used as an electroactive film. The introduction of these high dielectric functional groups and the improvement of the relative dielectric constant are proposed, for example, in International patent publication No. WO2014/105959 by the applicant of the present application.

The introduction of the high dielectric functional group may be performed by: a polyorganosiloxane or organohydrogen polysiloxane having a high dielectric functional group is used as a part or all of the component (a) or the component (B), or an organic additive having a high dielectric functional group, a non-reactive organosilicon compound having a high dielectric functional group, or the like is added to the curable composition. In the polyorganosiloxane or organohydrogen polysiloxane as the component (a) or (B), 10 mol% or more, preferably 20 mol% or more, more preferably 40 mol% or more of all substituents on the silicon atom thereof are substituted with a highly dielectric functional group, from the viewpoint of improving the miscibility with the curable composition and the relative dielectric constant of the cured product.

The kind of the high dielectric functional group introduced into the polyorganosiloxane cured film is not particularly limited, and preferably, examples thereof may be shown: a) a halogen atom and a halogen atom-containing group represented by 3, 3-trifluoropropyl group or the like, b) a nitrogen atom-containing group represented by cyanopropyl group or the like, c) an oxygen atom-containing group represented by carbonyl group or the like, d) a heterocyclic group such as imidazolyl group or the like, e) a boron-containing group such as borate group or the like, f) a phosphorus-containing group such as phosphine group or the like, and g) a sulfur-containing group such as thiol group or the like, it is preferable to use a halogen atom and a halogen atom-containing group containing fluorine atoms.

In the present invention, it is preferable that the high dielectric functional group is introduced into a part or the whole of the component (A) or the component (B) as represented by (C) _p F _2p+1 ) R- (R is an alkylene group having 1 to 10 carbon atoms, and p is an integer of 1 to 8 inclusive). Such fluoroalkyl groups provide cured products excellent in relative permittivity, and each component has fluorine atoms, thereby improving the compatibility of each component and providing cured products excellent in transparency. Specific examples of such fluoroalkyl groups are trifluoropropyl, pentafluorobutyl, heptafluoropentyl, nonafluorohexyl, undecahydroheptyl, tridecafluorooctyl, pentadecafluorononyl, heptadecafluorodecyl. Among them, a preferable group is a group of p=1, i.e., trifluoropropyl group, from the viewpoints of dielectric characteristics, economy, ease of preparation, and moldability of the resulting curable polyorganosiloxane composition.

In addition to the above-mentioned components, the curable polyorganosiloxane composition of the present invention may contain other components as required as long as the object of the present invention is not impaired. As other components, there may be exemplified: hydrosilylation reaction inhibitors, mold release agents, insulating additives, adhesion improvers, heat resistance improvers, fillers, pigments, and other various additives known in the art. Specific examples thereof are the same as those proposed in the above-mentioned International patent publication WO2014/105959, for example.

The curable polyorganosiloxane composition of the present invention can be prepared by uniformly mixing the curable polyorganosiloxane with the components (a) to (C) that promote the curing reaction, preferably by uniformly mixing the components (a) to (C), and if necessary, by adding other optional components, and uniformly mixing the components. The components may be mixed at normal temperature using various mixers or kneaders, but may be mixed under heating if the components are not solidified during the mixing.

The order of blending the components is not particularly limited as long as the components are not cured during mixing. When not immediately used after mixing, the crosslinking agent (e.g., component (B)) and the component (e.g., component (C)) that promotes the curing reaction may be stored in a plurality of containers so as not to be present in the same container, and the components in all the containers may be mixed immediately before use.

The curing reaction of the curable polyorganosiloxane composition of the present invention is carried out at room temperature in the curing reaction based on the condensation reaction such as dehydration, dealcoholization, etc., but in the case of producing a polyorganosiloxane cured film by an industrial production process, it is usually carried out by heating the composition or exposing it to active energy rays. The heat-based curing reaction temperature is not particularly limited, but is preferably 50 ℃ or higher and 200 ℃ or lower, more preferably 60 ℃ or higher and 200 ℃ or lower, and still more preferably 80 ℃ or higher and 180 ℃ or lower. The time taken for the curing reaction depends on the structure of the above components (a), (B) and (C), but is usually 1 second or more and 3 hours or less. Generally, the cured product can be obtained by holding at 90℃to 180℃for 10 seconds to 30 minutes. The method for producing the film will be described later.

The active energy rays that can be used for the curing reaction include: ultraviolet rays, electron beams, radiation, and the like are preferable in terms of practicality. In the case of curing reaction by ultraviolet rays, it is desirable to add a catalyst for hydrosilylation reaction having high activity with respect to ultraviolet rays used, for example, bis (2, 4-pentanedionic acid) platinum complex, (methylcyclopentadienyl) trimethylplatinum complex. As the ultraviolet light generating source, a high-pressure mercury Lamp, a medium-pressure mercury Lamp, a Xe-Hg Lamp, a Deep ultraviolet Lamp (Deep UV Lamp) and the like are preferable, and the irradiation amount at this time is preferably 100mJ/cm ² ～8000mJ/cm ² 。

[ method for producing laminate ]

The laminate of the present invention can be obtained by a method for producing a laminate comprising a step of laminating two or more cured polyorganosiloxane films having different compositions, and a step of chemically bonding the laminated cured polyorganosiloxane films at their interfaces.

Step I: and a step of curing one curable polyorganosiloxane composition of two or more curable polyorganosiloxane compositions having different compositions, which are obtained by curing the curable polyorganosiloxane composition into a film shape, wherein at least a part of the functional groups involved in the curing reaction are common.

Step II: and a step of applying a curable polyorganosiloxane composition different from the step I to the polyorganosiloxane cured film of the step I or to a precursor thereof simultaneously with or after the step I, and performing a curing reaction to laminate a different polyorganosiloxane cured film on the polyorganosiloxane cured film of the step I.

Here, the polyorganosiloxane cured material film in the step I is preferably a dielectric layer, and the polyorganosiloxane cured material film in the step II is preferably an electrode layer, or vice versa.

In step I or step II, as a method of coating the curable polyorganosiloxane composition into a film shape, gravure coating, offset coating, indirect gravure, roll coating using an offset transfer roll coater or the like, reverse roll coating, air knife coating (air knife coat), curtain coating using a curtain coater (curtain flow coater) or the like, comma knife coating, mayer bar (mayer bar), and other known methods used for the purpose of forming a cured layer can be used without limitation. The curable polyorganosiloxane composition of the present invention may be applied in a plurality of layers.

In the laminate of the present invention, the cured polyorganosiloxane film after lamination has a structure in which the cured polyorganosiloxane film is chemically bonded at the interface thereof, and the structure is formed by bringing a thin layer (a state before complete curing) of the cured polyorganosiloxane composition in an uncured or semi-cured state, which is a precursor of the cured polyorganosiloxane film, into contact with the cured polyorganosiloxane film after curing or before curing, and then completely curing the cured polyorganosiloxane film by a method such as heating, whereby the reaction between the curable reactive groups proceeds at the interface of the cured polyorganosiloxane film. From the viewpoints of industrial production and production efficiency, the above-mentioned processes may be carried out by laminating a plurality of layers by allowing a curing reaction to proceed, or may be carried out by completely curing the whole by a method such as heating after laminating a plurality of thin layers of a curable polyorganosiloxane composition having curing reactivity in advance.

Preferably, the method for producing a laminate is exemplified by the following steps: after the curable polyorganosiloxane composition different from step I is applied in a film form, in a state where the applied layer of the curable polyorganosiloxane composition is uncured or semi-cured, the same step is optionally repeated two or more times to form a laminate of a cured polyorganosiloxane film or a precursor thereof and a layer of the curable polyorganosiloxane composition in an uncured or semi-cured state, and then the curing reaction for the applied layer of the curable polyorganosiloxane composition different from step I is completely performed to cure the cured polyorganosiloxane film, whereby a different cured polyorganosiloxane film is laminated on the cured polyorganosiloxane film of step I. In this case, for example, a curable polyorganosiloxane composition containing conductive fine particles is applied as a film on a polyorganosiloxane cured film as a dielectric layer, and the polyorganosiloxane cured film as a dielectric layer is further laminated in an uncured or semi-cured state, and the same procedure as described below is repeated.

Dielectric layer (cured film)/uncured or semi-cured electrode layer/.

After the laminate precursor is formed as described above, the entire laminate is cured by heating or the like, whereby a laminate can be obtained in which cured dielectric layers and electrode layers are alternately laminated and the interfaces of the two layers are chemically bonded.

The above-mentioned manufacturing method is particularly useful as a method for forming an electrode layer in a member for a transducer, and can industrially easily provide a laminate, an electronic component, or a member for a display device, in which the dielectric layer and the electrode layer are firmly bonded, and in which problems such as peeling and defects due to insufficient adhesion strength and follow-up properties are less likely to occur.

The laminate of the polyorganosiloxane cured product film of the present invention is useful as an electronic material, a member for a display device or a member for a transducer (including a sensor, a speaker, an actuator, and a generator), and particularly can be used as an electroactive film (including a high dielectric film) having an electrode layer, preferably as a member for an electronic component or a display device. As described above, the form of the electroactive film having high dielectric breakdown strength as a single layer or a laminated film is preferably a member for a transducer such as an actuator, and has a structure in which electrode layers are firmly bonded, and therefore is particularly useful for an actuator that is started up at a high voltage.

Examples

The present invention will be described below with reference to examples, but the present invention is not limited to these examples. The following compounds were used in the examples and comparative examples shown below. The physical properties of each cured film were measured by the following methods.

[ Shore A hardness ]

The cured film as the Electrode Layer (ELEC) was prepared by heating the curable organosiloxane composition at a curing temperature of 150 ℃ for 1 hour, and the cured film as the dielectric layer (DEAP) was prepared by heating the curable polyorganosiloxane composition at a curing temperature of 110 ℃ for 1 hour. The thickness of the cured sample was set to about 6mm. The shore a hardness of each of the obtained cured films was measured by the method according to JIS K6249 using DD2 (manufactured by polymer corporation). The results are shown in Table 1. When the curing is insufficient or too soft, the measurement is "impossible" for each reason.

[ modulus of elasticity ]

The elastic modulus of each curable polyorganosiloxane composition providing the electrode layer was measured by a viscoelasticity measuring apparatus (model MCR302, manufactured by An Dongpa). A Peltier element temperature control system and parallel plates 15mm in diameter were used and arranged in such a manner that the sample became 500 μm thick. It took 2.8 minutes to warm from 25 ℃ to 120 ℃ and then to maintain 120 ℃ to cure. The storage modulus (G') after 60 minutes from the start of the temperature rise is shown in table 1 as the elastic modulus.

[ measurement of volume resistivity ]

Name of measuring device: measured at room temperature using Loresta GP (Mitsubishi Chemical Analytech Co.). The probe used was PSP (Mitsubishi Chemical Analytech Co.). As described below, the average value, electrode thickness, and correction coefficient of the values obtained by measuring at least 14 points on the electrode layer formed on the cured polyorganosiloxane film as the dielectric layer and reading the values after stabilization are shown in table 1.

Component (a 1): two terminal vinyldimethylsiloxy-terminated dimethylsiloxane polymer (vinyl content: 0.24 mass%, degree of polymerization of siloxane: 300).

Component (a 2): two terminal vinyldimethylsiloxy-terminated, 3-trifluoropropylmethyl, dimethylsiloxane copolymer (vinyl content: 0.26 mass%, siloxane polymerization degree 193).

Component (b 1): two terminal trimethylsiloxy end-capped, dimethylsiloxy-methylhydrosiloxy-siloxane copolymer (silicon atom-bonded hydrogen content: 0.71 mass%).

Component (b 2): dimethylhydrosilyloxy end-capped dimethylsiloxane polymer (silicon atom bound water content: 0.02 mass%).

Component (b 3): both terminal trimethylsiloxy end-capped, dimethylsiloxane/3, 3-trifluoropropylmethylsiloxane/methylhydrosiloxane copolymer (silicon atom-bonded hydrogen content: about 0.23 mass%).

Component (b 4): dimethylhydrosilyloxy end-capped, dimethylsiloxane/3, 3-trifluoropropylmethylsiloxane copolymer (silicon atom-bonded hydrogen content: about 0.014 mass%).

Component (c 1): two terminal vinyl dimethylsiloxy-terminated dimethylsiloxane polymer solutions of platinum-1, 3-divinyl 1, 3-tetramethyldisiloxane complex (about 0.6 mass% based on platinum concentration).

Component (d): acetylene black (100% pressed product, manufactured by electric company).

Component (e 1): fumed silica treated with hexamethyldisilazane and 1, 3-bis (3, 3-trifluoropropyl) -1, 3-tetramethyldisilazane (product name before treatment: AEROSIL 200, BET specific surface area 200m 2/g).

Component (e 2): fumed silica treated with hexamethyldisilazane and 1, 3-bis (3, 3-trifluoropropyl) -1, 3-tetramethyldisilazane (product name before treatment: AEROSIL 50, BET specific surface area 50m 2/g).

Component (e 3): fumed silica treated with hexamethyldisilazane (product name before treatment: AEROSIL 200, BET specific surface area 200m ² /g)。

Component (e 4): fumed silica treated with hexamethyldisilazane (product name before treatment: AEROSIL 50, BET specific surface area 50m ² /g)。

Component (f 1): 1-ethynyl-1-cyclohexanol.

Component (f 2): 1,3,5, 7-tetramethyl-1, 3,5, 7-tetravinyl-cyclotetrasiloxane.

Examples 1 to 3 and comparative examples 1 to 7 curable polyorganosiloxane compositions for providing electrode layers

As the liquid curable polyorganosiloxane composition, the above components were blended in weight% as shown in table 1. At this time, the silicon atom-bonded hydrogen atom (si—h) of the component (b) is present in the amount shown in table 1 per 1 mol of the unsaturated hydrocarbon group in the composition: (SiH/Vi) _ELEC Is used by way of example. The components were mixed by a rotation/revolution mixer (product name ARE-310, product name is THINKY Co., ltd.) to prepare a catalyst by mixing materials other than the component (c 1), adding the component (c 1), and further mixing by a rotation/revolution mixer under vacuum. The various physical properties are also shown in Table 1..

Examples 1 and 3 and comparative examples 1 to 7 curable polyorganosiloxane composition 1 for providing dielectric layer ]

As a liquid curable polyorganosiloxane composition, the following was compounded and prepared: the content of the component (a 2) was 68.34% by mass, the content of the component (b 3) was 5.06% by mass, the content of the component (b 4) was 5.06% by mass, the content of the component (c 1) was 0.10% by mass, the content of the component (e 1) was 18.69% by mass, the content of the component (e 2) was 2.46% by mass, and the content of the component (f 2) was 0.28% by mass. At this time, the silicon atom of component (b) is bonded with a hydrogen atom (si—h) per 1 mol of unsaturated hydrocarbon group in the composition: (SiH/Vi) _DEAP Is used in an amount of about 1.2 mol. The hardness of the resulting cured polyorganosiloxane was Shore A37.

[ curable polyorganosiloxane composition for dielectric layer 2] < DEAP sheet example 2]

As a liquid curable polyorganosiloxane composition, the following was compounded and prepared: the content of the component (a 1) was 70.59% by mass, the content of the component (b 1) was 0.99% by mass, the content of the component (b 2) was 3.83% by mass, the content of the component (c 1) was 0.10% by mass, the content of the component (e 3) was 20.10% by mass, the content of the component (e 4) was 4.35% by mass, and the content of the component (f 1) was 0.04% by mass. At this time, the silicon atom of component (b) is bonded with a hydrogen atom (si—h) per 1 mol of unsaturated hydrocarbon group in the composition: (SiH/Vi) _DEAP Is used in an amount of about 1.2 mol. The hardness of the resulting cured polyorganosiloxane was Shore A39.

[ formation of dielectric layer (film) of example/comparative example ]

The curable polyorganosiloxane composition providing the dielectric layer was applied as a film on a PET substrate having a release layer (release liner) using a coater, and cured in an oven at 110 ℃ for 60 minutes, thereby producing a film having a thickness of 0.1 mm.

[ formation of electrode layer of example/comparative example ]

The curable polyorganosiloxane composition for providing an electrode layer described in Table 1 was diluted with a low molecular weight siloxane-based solvent (OST-20, manufactured by DOWSILICONES) so that the electrode material concentration became 10% by weight. A circular cap was attached to one surface of the dielectric layer (film) having a thickness of 0.1mm produced in the above-described manner, and a dilution liquid was applied by spraying from above the cap so that 16 circular electrodes having a diameter of 13.5mm were formed. After coating, the coating was left under vacuum at 60℃for about 12 hours. Then, the electrode was covered with a PET base material having a release layer (release liner), and the electrode was pressed at room temperature. The film of the base PET was peeled off and heated at 120℃for 60 minutes, whereby an electrode having a thickness of 10 μm to 13 μm was formed.

[ evaluation of adhesion of dielectric layer/electrode layer: peel test ]

An adhesive tape (trade name: NITOFLON (registered trademark) 0.08 manufactured by niton) was attached to a circular electrode layer formed on one side of a dielectric layer (film) by the above-described method, and the adhesion between the dielectric layer and the electrode layer was evaluated by peeling after leaving the film at room temperature for 10 minutes. At this time, if the electrode layer was not peeled off with the tape and remained almost on the dielectric layer (film), it was evaluated as "usable", and the case where the electrode layer was peeled off with the tape was evaluated as "unusable", and table 1 was entered. When the electrode layer is peeled off from the surface of the dielectric layer toward the tape side and transferred, it is considered that sufficient chemical bonding is not formed at the interface between the electrode layer and the surface of the dielectric layer, and the adhesion and bonding force are weak.

TABLE 1

The dielectric layers and electrode layers of examples 1 to 3 had a structure in which the electrode layers were not peeled off in the peeling test and the two layers were firmly adhered to each other. On the other hand, in comparative examples 1 to 7 in which the SiH/Vi ratio of the two layers was not designed to fall within the preferable range, the electrode layers were peeled off in the peeling test, and it was considered that the adhesion and the follow-up property of the two layers were insufficient.

Claims

1. A laminate having a structure in which two or more cured polyorganosiloxane films having different compositions are laminated, wherein the laminated cured polyorganosiloxane films have a structure in which the cured polyorganosiloxane films are chemically bonded at the interfaces of the films, and wherein the two or more cured polyorganosiloxane films are obtained by curing a curable polyorganosiloxane composition that is common to at least a part of the functional groups involved in the curing reaction.

2. The laminate according to claim 1, wherein,

at least one of the cured polyorganosiloxane films after lamination has a volume resistivity of 10 ² Omega cm or less.

3. The laminate according to claim 1 or 2, wherein,

at least one of the cured polyorganosiloxane films after lamination has a shear storage modulus G' at 120 ℃ of 5.0X10 ⁴ Pa～1.5×10 ⁵ Pa.

4. The laminate according to any one of claim 1 to 3,

at least one of the cured polyorganosiloxane films after lamination contains conductive fine particles.

5. The laminate according to claim 4, wherein,

the conductive fine particles are fine particles containing at least one conductive carbon selected from the group consisting of conductive carbon black, graphite, and vapor grown carbon VGCF.

6. The laminate according to any one of claims 1 to 5, wherein,

at least one of the laminated cured polyorganosiloxane films is an electrode layer, and the other is a dielectric layer.

7. The laminate according to any one of claims 1 to 6, wherein,

a curable polyorganosiloxane composition which is cured to provide a polyorganosiloxane cured product film, comprises at least:

(B) An organohydrogen polysiloxane having at least two silicon-bonded hydrogen atoms in the molecule in an amount of 0.5 to 2.5 moles of silicon-bonded hydrogen atoms in the present component relative to 1 mole of the total amount of carbon-carbon double bonds in the composition; and

(C) An effective amount of a hydrosilylation catalyst,

the cured polyorganosiloxane film after lamination has a structure in which the above-mentioned components (a) and (B) are chemically bonded to each other by hydrosilylation reaction at the interface.

8. The laminate according to claim 7, wherein,

the cured polyorganosiloxane film after lamination is obtained by curing a curable polyorganosiloxane composition having a different composition,

One of the cured polyorganosiloxane films is (I) a cured polyorganosiloxane composition obtained by curing a curable polyorganosiloxane composition having more than 1.0 mol and not more than 2.0 mol of silicon atom-bonded hydrogen atoms relative to 1 mol of the total amount of carbon-carbon double bonds in the composition,

the other polyorganosiloxane cured film is (II) a cured film obtained by curing a curable polyorganosiloxane composition in which the silicon atom-bonded hydrogen atoms in the organohydrogen polysiloxane component are 0.5 to 1.0 mol based on 1 mol of the total amount of carbon-carbon double bonds in the composition.

9. The laminate according to claim 7 or 8, wherein,

one cured polyorganosiloxaneThe film contains conductive fine particles, and the mass of the hydrogen atom bonded to the silicon atom in the organopolysiloxane component is 1 mol based on the total amount of carbon-carbon double bonds in the composition [ SiH/Vi ]] _Elec Is not less than 0.5 mol but not more than 1.0 mol,

the other polyorganosiloxane cured material film is a dielectric layer, contains no conductive fine particles, and has a mass [ SiH/Vi ] of silicon atom-bonded hydrogen atom in the organohydrogen polysiloxane component of 1 mol based on the total amount of carbon-carbon double bonds in the composition ] _DEAP ，

[SiH/Vi] _Elec /[SiH/Vi] _DEAP The value of (2) is in the range of 0.33 to 0.85.

10. The laminate according to any one of claims 1 to 9, wherein,

the polyorganosiloxane cured film as the electrode layer is laminated on at least one surface of the polyorganosiloxane cured film as the dielectric layer, and the laminated polyorganosiloxane cured film has a structure in which chemical bonds are formed at the interface thereof.

11. A member for a transducer constituted by the laminate according to any one of claims 1 to 10.

12. A transducer comprising a laminate according to any one of claims 1 to 10.

13. An electronic part or a display device comprising the laminate according to any one of claims 1 to 10.

14. A method of manufacturing the laminate according to any one of claims 1 to 10, the method comprising:

step I: a step of curing one curable polyorganosiloxane composition of two or more curable polyorganosiloxane compositions having different compositions, which are obtained by curing one of the curable polyorganosiloxane compositions into a film shape, wherein at least a part of the functional groups involved in the curing reaction are common;

15. The method for producing a laminate according to claim 14, wherein,

the cured polyorganosiloxane film in step I is a dielectric layer, and the cured polyorganosiloxane film in step II is an electrode layer.

16. The method for producing a laminate according to claim 14 or 15, wherein,

the above-mentioned step II includes the following steps: after the curable polyorganosiloxane composition different from step I is applied in a film form, in a state where the applied layer of the curable polyorganosiloxane composition is uncured or semi-cured, the same step is optionally repeated two or more times to form a laminate of a cured polyorganosiloxane film or a precursor thereof and a layer of the curable polyorganosiloxane composition in an uncured or semi-cured state, and then the curing reaction for the applied layer of the curable polyorganosiloxane composition different from step I is completely performed to cure the cured polyorganosiloxane film, whereby a different cured polyorganosiloxane film is laminated on the cured polyorganosiloxane film of step I.

17. A method of forming an electrode layer in a member for a transducer, the method of forming an electrode layer in a member for a transducer comprising the method of manufacturing a laminate according to any one of claims 14 to 16.